Although a wealth of knowledge on the behavior of steel moment frame structures has been gained from past experimental studies, there are only a limited number of system-level tests examining seismic response near collapse. Such experimental data is essential to validate and improve analytical tools that generally rely on empirical and mechanical component-level models to capture the global system behavior. In view of the limited experimental data, a series of tests were conducted at the Network for Earthquake Engineering Simulation equipment site at the University at Buffalo. Hybrid simulation with substructuring was employed as a cost-effective alternative for large-scale system-level testing of large subassemblies. The ½-scale specimen, consisting of a 1½-bay by 1½-story subassembly, was designed to capture the behavior and interactions of beams, columns, panel zones, and the composite floor slab. The experimental setup permitted the application of lateral as well as varying vertical forces on the test specimen while maintaining realistic boundary conditions on the subassembly. This paper presents a description of the seismic performance of the different components of the tested subassembly.